1. Technical Field
The present invention relates to a display substrate and a method of manufacturing the same, and more particularly, a display substrate for displaying an image and a method of manufacturing the same.
2. Discussion of the Related Art
A liquid crystal display device which is a display device for displaying images includes a display substrate, a counter substrate disposed opposite the display substrate, and a liquid crystal layer disposed between the two substrates.
Generally, a display substrate includes gate wirings, data wirings, thin film transistors (TFTs) and pixel electrodes that are formed on the transparent substrate to drive a plurality of pixels independently. The counter substrate includes red, green and blue color filters, a black matrix and a common electrode opposite the pixel electrode.
As is well known, ON current (Ion) of the TFT is improved as W/L, a ratio of channel width and channel length of TFT, is increased and as effective mobility is increased. However, in conventional TFT structures in which the channel is formed in a direction parallel to the surface of the substrate, there is a limitation in reducing the channel length (L) due to an exposure limitation. Thus, a vertical TFT in which the channel is formed in a direction perpendicular to the substrate has been introduced recently. In this case, the channel length (L) can be reduced more than the conventional structures because the channel length (L) can be controlled by controlling the thickness of the channel layer, and therefore, ON current (Ion) can also be improved to some extent. However, even in such a case, there is a need for increasing ON current by increasing the effective mobility.